[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [PATCHv2 19/20] snapshot: qemu: Add support for external snapshot deletion.



On 11/09/12 12:36, Peter Krempa wrote:
On 11/06/12 23:39, Eric Blake wrote:
On 11/01/2012 10:22 AM, Peter Krempa wrote:
This patch adds limited support for deleting external snaphots. The

s/snaphots/snapshots/

machine must not be active and only whole subtrees of snapshots can be
deleted as reparenting was not yet implemented for external snapshots.

These are reasonable restrictions for the first implementation.  We may
relax some of them later - for example, if qemu adds support for doing
blockcommit from the active layer, then that would let us do a live
deletion of an external snapshot.

---

[...]



6. I created an external checkpoint, did some experiments, and want to
remember those results; but I also want to go back to the checkpoint and
do some more experiments on a different branch.  Solution: here, we need
the ability to create NEW qcow2 files that also wrap the common base
image.  Since virDomainRevertToSnapshot doesn't have a way for us to
pass in the new file names we wish to use, this needs to go through
virDomainSnapshotCreateXML, which needs a new flag that says that we are
simultaneously reverting to the state of an existing snapshot and
creating a new snapshot from that point rather than at the current state
of execution.

I saw your submission. But this will probably have to be a 2 step
procedure:

1) create a snapshot at the original branch to have a point to return to
2) create the branch and revert to that point in time

Otherwise it will be hard to return to that original branch. Basically
we need some kind of "current" snapshot in each of the branches.
Technically that should be easy for a management application, but it
won't be that comfortable to do in virsh.

An option would be automatically creating a "current" snapshot when leaving a branch that would re-use the disk image files, but will need to be automatically deleted as soon as the restore to it is complete.



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]